AN INVESTIGATION OF MITOCHONDRIAL INNER MEMBRANES BY RAPID-FREEZE DEEP-ETCH TECHNIQUES
AN INVESTIGATION OF MITOCHONDRIAL INNER MEMBRANES BY RAPID-FREEZE DEEP-ETCH TECHNIQUES
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DOI：
10.1083/jcb.108.6.2233
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发表时间：
1989-06-01
影响因子：
7.8
通讯作者：
FOK, AK
中科院分区：
文献类型：
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作者：
ALLEN, RD;SCHROEDER, CC;FOK, AK
通过快速冷冻，然后冷冻断裂和深蚀刻的物理固定提供了可能看到线粒体内膜上颗粒天然状态下的三维结构的手段。我们已经使用这些技术来研究草履虫的管状嵴，希望确定F1复合物的排列，它们的丰度，以及在膜中的位置。我们还寻求有关这些膜中其他呼吸复合物的信息。我们的研究结果，支持立体对，表明F1复合物被安排为一个双行的颗粒间隔12 nm沿着每一行作为拉链以下的螺旋形管状嵴的外曲线的全长。每平方微米的50纳米管状嵴表面平均有1,500个高度有序的F1复合物。F1复合物在其天然状态下肯定位于膜外。其他颗粒子集，也非随机排列，被视为。一个这样的群体位于沿着内螺旋曲线由13 nm宽的大颗粒组成，其中心到中心间隔为30 nm。这样的颗粒，因为它们的大尺寸和相对丰度相比，F1单位，类似于呼吸复合物的复合物I。任何试图理解草履虫中呼吸复合物与F0 F1 ATP酶偶联的模型都必须考虑到这些完整膜复合物中至少一些的相对高度的有序性和潜在的不动性。
Physical fixation by rapid freezing followed by freeze-fracture and deep-etching has provided the means for potentially seeing the three-dimensional arrangment in the native state of particles on mitochondrial inner membranes. We have used these techniques to study the tubular cristae of Paramecium in the hope of determining the arrangement of F1 complexes, their abundance, and location in the membranes. We also sought information regarding other respiratory complexes in these membranes. Our results, supported by stereo pairs, show that F1 complexes are arranged as a double row of particles spaced 12 nm along each row as a zipper following the full length of the outer curve of the helically shaped tubular cristae. There are an average of 1,500 highly ordered F1 complexes per micrometer squared of 50-nm tubular cristae surface. The F1 complexes definitely lie outside the membranes in their native state. Other particles subsets, also nonrandomly arrayed, were seen. One such population located along the inner helical curve consisted of large 13-nm-wide particles that were spaced at 30 nm center-to-center. Such particles, because of their large size and relative abundance when compared to F1 units, resemble complex I of the respiratory complexes. Any models attempting to understand the coupling of respiratory complexes with F0F1 ATPase in Paramecium must take into account a relatively high degree of order and potential immobility of at least some of these integral membrane complexes.